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Dion V, Schumacher N, Masar N, Pieltain A, Tocquin P, Lesoinne P, Malgrange B, Vandenbosch R, Franzen R. Cyclin-dependent kinase 7 contributes to myelin maintenance in the adult central nervous system and promotes myelin gene expression. Glia 2022; 70:1652-1665. [PMID: 35488490 DOI: 10.1002/glia.24186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 04/08/2022] [Accepted: 04/21/2022] [Indexed: 11/08/2022]
Abstract
Mechanisms regulating oligodendrocyte differentiation, developmental myelination and myelin maintenance in adulthood are complex and still not completely described. Their understanding is crucial for the development of new protective or therapeutic strategies in demyelinating pathologies such as multiple sclerosis. In this perspective, we have investigated the role of Cyclin-dependent kinase 7 (Cdk7), a kinase involved in cell-cycle progression and transcription regulation, in the oligodendroglial lineage. We generated a conditional knock-out mouse model in which Cdk7 is invalidated in post-mitotic oligodendrocytes. At the end of developmental myelination, the number and diameter of myelinated axons, as well as the myelin structure, thickness and protein composition, were normal. However, in young adult and in aged mice, there was a higher number of small caliber myelinated axons associated with a decreased mean axonal diameter, myelin sheaths of large caliber axons were thinner, and the level of some major myelin-associated proteins was reduced. These defects were accompanied by the appearance of an abnormal clasping phenotype. We also used an in vitro oligodendroglial model and showed that Cdk7 pharmacological inhibition led to an altered myelination-associated morphological modification combined with a decreased expression of myelin-specific genes. Altogether, we identified novel functions for Cdk7 in CNS myelination.
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Affiliation(s)
- Valérie Dion
- Laboratory of Nervous System Disorders and Therapies, GIGA Neurosciences, University of Liège, Liège, Belgium
| | - Nathalie Schumacher
- Laboratory of Nervous System Disorders and Therapies, GIGA Neurosciences, University of Liège, Liège, Belgium
| | - Nathalie Masar
- Laboratory of Nervous System Disorders and Therapies, GIGA Neurosciences, University of Liège, Liège, Belgium
| | - Alexandra Pieltain
- Laboratory of Nervous System Disorders and Therapies, GIGA Neurosciences, University of Liège, Liège, Belgium
| | - Pierre Tocquin
- CARE PhytoSYSTEMS, Integrative Biological Sciences, University of Liège, Liège, Belgium
| | - Pierre Lesoinne
- Laboratory of Nervous System Disorders and Therapies, GIGA Neurosciences, University of Liège, Liège, Belgium
| | - Brigitte Malgrange
- Laboratory of Developmental Neurobiology, GIGA Stem Cells & GIGA Neurosciences, University of Liège, Liège, Belgium
| | - Renaud Vandenbosch
- Laboratory of Developmental Neurobiology, GIGA Stem Cells & GIGA Neurosciences, University of Liège, Liège, Belgium.,Division of Histology, Department of Biomedical and Preclinical Sciences, University of Liège, Liège, Belgium
| | - Rachelle Franzen
- Laboratory of Nervous System Disorders and Therapies, GIGA Neurosciences, University of Liège, Liège, Belgium
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